1. Field of the Invention
The present invention relates to a memory component and a memory device, which store information in accordance with a change of the electrical characteristics of a memory layer that includes an ion source layer and a high resistance layer.
2. Description of the Related Art
As semiconductor nonvolatile memories for data storage, NOR type or NAND type flash memories are generally used. According to these semiconductor nonvolatile memories, however, a large voltage is necessary for write and erase operations, and the number of electrons that are injected into a floating gate is limited causing a limit on the miniaturization of the memory.
Recently, resistance change type memories, such as ReRAM (Resistance Random Access Memory), PMC (Programmable Metallization Cell), or the like, have been proposed as next-generation nonvolatile memories that can overcome the limit on miniaturization (for example, Nature Material 1614 p 312 (2006),U.S. Pat. No. 5,761,115 Jun. 2, 1998 Axon, and Sawa Materials today 11 28 (2008)). These memories have a simple structure provided with a resistance change layer between two electrodes. Also, according to a memory disclosed in JP-A-2006-196537, an ion source layer and an oxide film (thin film for memory) are provided between a first electrode and a second electrode instead of the resistance change layer. In these resistance change type memories, it is considered that atoms or ions move according to heat or electric fields and thus a conduction path is formed to change the resistance value.
However, in order to realize a large capacity in the resistance change type nonvolatile memory through a front-end semiconductor process, low-voltage and low-current operation is necessary. This is because as driving transistors are miniaturized, their driving current and voltage become lowered. That is, in order to realize a miniaturized resistance change type nonvolatile memory, it is necessary that the memory has a function capable of being driven by miniaturized transistors. In addition, in order to realize a low-current operation, it is also necessary to maintain a resistance state (data) that is rewritten at low current and high speed (short pulse on the nanosecond order).